Postmeliorative Transformation of Carbonate and Gypsum Profiles of Solonetzic Soils in the Dry Steppe Zone

Abstract

It is shown that deep ameliorative plowing with destruction and disintegration of solonetzic horizons changes the morphology of the profile and water-physical properties of soils in solonetzic soil complexes of the dry-steppe zone. This results in a more active migration of calcium salts and dissolution and recrystallization of carbonate and gypsum pedofeatures. Data on the tendencies of changes in the contents of carbonates and gypsum and the morphology of carbonate and gypsum pedofeatures at the macro- and mesolevels are given for the reclaimed high-carbonate deep-gypsum solonetzic soils and light chestnut soils (Protosalic Solonetzes (Loamic, Columnic, Cutanic, Differentic, Ochric); Eutric Cambisols (Loamic, Protocalcic, Ochric)). Reclaimed solonetzes and light chestnut soils are characterized by an increase in the carbonate content of the plow horizon. This attests to the accumulation of carbonates in the plow layer of these soils, which is a new elementary pedogenic process for them. The mechanism of this process is described. It includes dissolution of carbonates in the carbonate-accumulative horizon in spring followed by the upward migration of dissolved carbonates upon the soil drying in summer.